设二维随机变量(X，Y)的概率密度为f(x，y)，则P{X﹥1}=____.()
A.∫1-∞dx∫+∞-∞f(x,y)dy B.∫+∞1dx∫+∞-∞f(x,y)dy C.∫1-∞f(x,y)dx D.∫+∞1f(x,y)dx正确答案B
设二维随机变量(X，Y)的概率密度为f(x，y)，则P{X﹥1}=____.()
A.∫1-∞dx∫+∞-∞f(x,y)dy B.∫+∞1dx∫+∞-∞f(x,y)dy C.∫1-∞f(x,y)dx D.∫+∞1f(x,y)dx正确答案B
